Focusing lens mount for cameras



April 15, 1941. MIHALY] 2,238,498

FOCUSING LENS MOUNT FOR CAMERAS Filed Oct. 11, 1939 Jaszm MHALW INVENTORM.

A TTORNE YS Patented Apr. 15, 1941 UNITED STATES PATENT OFFICE FOCUSINGLENS MOUNT FOR CAMERAS Joseph Mihalyi, Rochester, N. Y., assignor toEastman Kodak Company, Rochester, N. Y., a corporation of New JerseyApplication October 11, 1939, Serial No. 298,951

13 Claims.

is invention relates to photography and more particularly to focusinglens mounts for photographic cameras. One object of my invention is toprovide a structure of the class described in which the objective may bequickly brought into a focusing position. Another object of my inventionis to provide a mechanism for quickly bringing the objective into afocusing position and for accurately adjusting the objective to anyselected focal distance after having been quickly positioned at theinfinity position. Another object of my invention is to provide anobjective mount in which the greater part of the movement to positionthe lens is a sliding movement after which a spiral movement of theobjective is used for focusing on various different focal distances.Still another object of my invention is to provide a pair of matingthread members which may be quickly and accurately mated by a slightrotative movement of the mount. A still further object of my inventionis to provide mating threads with angular ends or teeth some of whichextend axially of others so that they will immediately mesh when a lenstube is drawn out to a proper position and other objects will appearfrom the following specification the novel features being pointed out inthe claims at the end thereof.

Coming now to the drawing wherein like reference characters denote likeparts throughout, Fig. 1 is a front plan View of a camera constructed inaccordance with and embodying a preferred form of my invention.

Fig. 2 is a fragmentary enlarged part section and part elevation takenon line 2-2 of Fig. 1.

Fig. 3 is a fragmentary detail section showing the relationship of thelens tube and focusing mount structure when the lens tube has been drawnout to substantially an infinity position.

Fig. 4 is a view similar to Fig. 3 but with the parts in a collapsed orfolded position.

Fig. 5 is a fragmentary plan taken from the back of the camera andshowing the connection of the focusing knob with an adjusting ring.

Fig. 6 is an enlarged sectional view of a focusing ring which is mountedon the front wall of the camera, and

Fig. 7 is a diagrammatic view showing the relationship of mating threadson the focusing ring and tubular lens mount.

In cameras and particularly in compact cameras of the so-calledminiature type, a camera objective is frequently mounted on a tubularsupport the tubular support being in turn carried by the camera body. Myinvention relates to such cameras and particularly to a method ofcollapsing the camera into a compact or folded position and to astructure for quickly opening the camera into a picture taking position.

In accordance with a preferred embodiment of my invention, the cameramay comprise a camera body I on which there may be mounted a filmwinding key 2 and a housing 3 which may contain range finder elements 4and 5. The front wall of the camera is preferably covered by a metalplate 6 which may be attached to the camera body by screws 1 this metalplate supporting an annular thread member 8 which carries multipleinternal threads 9 and which is provided with at least one axial slotID.

The annular thread member 8 is mounted in a circular opening II in theplate 6 and may freely turn since there is a collar l2 attached to thering by means of one or more screws [3 this collar being so adjustedthat free rotative movement of the annular thread member may take placewhen a handle M, which is carried by the annular thread member, isturned. However, this turning movement can only occur when the threads 9are mating with threads I5 carried by the tubular extension l6 whichwill be hereinafter more fully described.

In the present embodiment of my invention an operator may, as abovedescribed, use the handle M for fine adjustment of the objective 0carried in a shutter I! to adjust the objective for various focalpositions or a second focusing member may be used. This member consistsof a knob 18 pivot-ally mounted on the plate 6 and being carried by ashaft IS on which a gear 20 is carried so that this gear, by meshingwith a gear 2| mounted to turn on a stud 22, may turn the gear segment23 which is here shown as forming a part of the collar l2 which includesthe thread 9 engaging the tubular extension IS. The thread 8 mayslidably engage the smooth exterior wall of extension IE or may engagethe thread 9 thereof. Thus either the knob l8 or the handle 14 may beturned to adjust the objective to various focal positions.

If the camera is in a collapsed or folded posit1on, in order to takepictures, the ring 25 surrounding the shutter I! which can beconveniently knurled, is drawn axially of the ob ective. This movementcauses the tubular extension 16 to move outwardly and, since the tubularextension is provided with a web 26, and

this web extends axially of the tubular extension,

the web slides in the groove Ill. As long as web 26 lies in the grooveID, the handle l4 cannot turn, since the web 26 is carried by the tubeIt which cannot turn due to the pin 3| and the guideway 39. Thus, aslong as any part of the web 26 lies in the groove III, the annularthread member 9, together with the operating handle I4 and the focusingknob l8, are all held against movement. However, as soon as the tubularextension IE is drawn out until the web leaves the slot II], as shown inFig. 3, it is possible to focus the objective by either the handle l 4or the knob I8 because rotative movement is permitted. I find itconvenient to draw out the tubular extension to a distance sufiicient tobring the ob jective to or substantially to an infinity position so thatmovement from this point outwardly will cause the objective to focus onobjects which are closer to the camera.

The tubular extension It can never turn with respect to the camera bodyI because the camera body carries a pair of brackets 2! attached to thewalls 28 of the camera body by means of screws 29. These brackets areslotted at 30 to receive pins 3| extending inwardly on the tubularextension so that only movement axially of the objective is permitted.

When parts are drawn to the position shown in Fig. 3 in which the web 26has passed through the slot In, it is desirable to immediately mesh themating screw threads 9 and I5. Normally if all of the mating threadswere out off at right angles to the axis of the objective, it would bedificult to bring the threaded members into mesh. However, I haveovercome this difficulty by cutting off various threads of the matingthreads 9 and I5 at different points axially of the objective so thatcertain threads project longitudinally with respect to certain otherthreads so that even a slight turning movement of the annular threadmember 9 will immediately mesh the threads.

It will be noted from Fig. 2 that every other thread I5 is cut off adistance D shorter than the other threads so that each alternate threadprojects outwardly from its next adjacent thread. Similarly, from Fig. 6it will be noticed that the annular thread member. 8 is provided withthreads some of which extend to the end wall of the ring whereas othersextend only a distance D to the edge of the ring and. thus projectaxially of the other threads. The reason for this is as follows: sincethe tubular extension [6 is drawn to the Fig. 3 position, the firstslight turning movement causes the outwardly projecting thread ends,which I prefer to call teeth, of one threaded element to enter themating corresponding threads of the other threaded element so that aproper meshing is immediately obtained. In fact it is impossible withthis construction to turn one thread member relative to the otherwithout meshing the threads during this turning movement.

It will be obvious that in order to secure this result it is onlynecessary to provide one or more pairs of mating threads 9 and It withshort and long teeth and it is not necessary to provide every otherthread with a tooth which projects axially of its next adjacent one.However, I find this a convenient construction and have so illustratedthe quick mating threads in the preferred embodiment of my invention.

The operation of my quick focusing camera is exceedingly simple and canbe accomplished in much less time than it takes to describe it. As-

suming that the camera parts are in the folded position shown in Fig. 4and it is desired to take a picture; the flange 25 is grasped by theoperator who draws the tubular extension Hi outwardly. During thisoutward movement, since the web 26 slides in the slot Ml, turningmovement of the annular thread member 8 is prevented until the partsreach the position shown in Fig. 3. I find it convenient to have thisposition a position in which the objective is adjusted to focus onobjects at feet (in the case of relatively short focal lengthobjectives). The tubular extension automatically comes to a stop at thisposition because the ends or teeth of the mating threads 9 and i5 reacha mating position and stop further sliding movement of the tubularextension it.

Should the operator desire to focus on objects closer than 100 feet, hemay then move either the handle M or the knob l 8. By so doing, movementis transmitted to the annular thread member 8 and the projecting teethof the mating threads 9 and i5 immediately engage and, by sliding one onthe other, transmit focusing movement to the tubular extension It. Thisfocusing movement is smooth and easy and can be accurately accomplishedbecause of the angle of the mating threads 9 and I5. If the cameraobjective is of a very short focal length, it is desirable to have thepitch of these threads quite slight so that a relatively large angularmovement of the annular thread member will cause comparatively littleaxial movement. On the other hand, if this focusing structure is appliedto an objective having a long focal length, the pitch of the threads canbe greatly increased because considerably more movement of the objectivefor focusing on objects from 100 feet to 3 feet, for instance, will berequired.

When the object has been focused and a picture has been taken, if thecamera is to be folded, the natural way of accomplishing the foldingmovement is to swing the knob M until the parts are returned to theposition shown in Fig. 3 in which position the slot I9 is automaticallyaligned with the Web 2%. In this position, as indicated in Fig. 3, it isonly necessary to thrust inwardly upon the tubular extension causing theparts to move to their fully collapsed position in Fig. 4. As soon asthe web enters the slot II], the annular threaded member can no longerbe turned so that both the handle i l and the knob I8 are definitelylatched in their inoperative position and will remain so latched untilthe parts are again moved to the erect or picture taking position. asabove described.

With the usual type of threads, whether the threads be single ormultiple it is difiicult to cause the threads to mesh, because the flatedges of two threaded areas may turn without the threads being actuallybrought into mesh. However, with my improved threads, in which certainthreads project axially of the others, the first turning movement Willcause the projecting threads to immediately mesh, and when so meshed,the objective may be fOCLlSSd by turning either the handle M or thefocusing knob- I8.

I claim:

1. In a focusing lens mount for cameras, the combination with a support,of an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slidably mounted in the threaded member and includingthreads adapted to mesh with the threads of the annular member, meansfor sliding the tubular extension until the threaded areas of thetubular extension and annular member lie adjacent and meansv for causingthe threaded areas to mesh rapidly comprising teeth in the two sets ofthreads projecting axially from other threads whereby turning movementof the tubular extension relative to the annular threaded member maymesh the threaded areas.

2. In a focusing lens mount for cameras, the combination with a support,of. an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slidably mounted in the threaded member and includingthreads adapted to mesh with the threads of the annular member, meansfor sliding the tubular extension until the threaded areas of thetubular extension and annular member lie adjacent, and means for causingthe threaded areas to mesh rapidly comprising teeth on the ends ofcertain threads of each threaded area extending axially beyond otherteeth-forming the ends of certain other threads whereby the teeth maylie in staggered relation to be meshed by rotative movement of onethreaded member relative to the other.

3. In a focusing lens mount for cameras, the combination with a support,of an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slidably mounted in the threaded member and includingthreads adapted to mesh with the threads of the annular member, meansfor slid ing the tubular extension until the threaded areas of thetubular extension and annular member lie adjacent, and means for causingthe threaded areas to mesh rapidly comprising teeth on the ends of thethreads of the threaded members, each alternate tooth extending axiallyof the next adjacent tooth whereby rotative movement of one threadedmember relative to the other may mesh the gears through theinterengaging teeth and the tubular extension may move axially relativeto the support.

4. In a focusing lens mount for cameras, the combination with a support,of an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slid- L;

ably mounted in the threaded member and including threads adapted tomesh with the threads of the annular member, means for sliding the tubular extension until the threaded areas of the tubular extension andannular member lie ad- I jacent tooth whereby rotative movement of one athreaded member relative to the other may mesh the gears through theinterengaging teeth and the tubular extension may move axially relativeto the support, and a pin and a slotted two-part guideway, the tubularextension carrying one part and the support carrying the other partwhereby the movement of the tubular extension relative to the annularmember may be guided to prevent turning.

5. In a focusing lens mount for cameras, the combination with a support,of a threaded member revolubly carried thereby, a tubular extensionhaving a threaded area thereon and carrying an objective, a pin and aslotted guideway carried by the tubular extension and support forguiding the tubular extension to slide axially of the mount until thethreaded areas of the support and tubular extensions approach eachother, an objective carried by the tubular extension, and means forimmediately meshing said threaded area comprising a number of threads oneach threaded area of slightly greater length than other of thethreadson each threaded area Whereby the threads may be quickly meshed androtative movement of the threaded member carried by the mount may focussaid objective carried by the tubular extension.

6. In a focusing lens mount for cameras, the combination with a support,of a threaded member revolubly carried thereby, the top of threadshaving flat surfaces forming a cylindrical slide- Way, a tubularextension having a threaded area thereon and carrying an objective andof a diameter to slide inthe slideway formed by the flat top of thethreads, a pin and a slotted two-part guide, said tubular extensioncarrying one part and said support carrying the other part for guidingthe tubular extension to slide axially of the mount until the threadedareas of the support and tubular extensions approach each other, anobjective carried by the tubular extension, and means for immediatelymeshing said threaded areas comprising a number of threads on eachthreaded area of slightly greater length than other of the threads oneach threaded area Whereby rotative movement of the threaded membercarried by the mount may focus said objective carried by the tubularextension.

'7. In a focusing lens mount for cameras, the combination with anapertured support, of a threaded member revolubly carried thereby, atubular extension having a threaded area thereon and carrying anobjective, a pin and a slotted two-part guideway, said tubular extensioncarrying one part and said support carrying the other part for guidingthe tubular extension to slide axially of the mount until the threadedareas of the support and tubular extensions approach each other, anobjective carried by the tubular extension, and means for immediatelymeshing said threaded areas comprising teeth on the ends of the threadsof the threaded members comprising angular edges of the threads, certainof the teeth projecting axially of certain of the other teeth to formprojections engageable by moving the tubular extension relative to theannular threaded member whereby movement of the latter may move theformer axially of the apertured support to focus the objective.

8. In a focusing lens mount for cameras, the combination with a support,of an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slidably mounted in the threaded member and ineludingthreads adapted to mesh with the threads of the annular member, meansfor sliding the tubular extension until the threaded areas of thetubular extension and annular member lie adjacent, means for causing thethreaded areas to mesh rapidly through a turning movement of onethreaded area relative to the other, and means carried by the supportand tubular extension for preventing a turning movement of the tubularextension, a second means carried by the tubular extension and annularthreaded member for preventing the latter from turning until thethreaded areas are substantially in meshing position.

9. In a focusing lens mount for cameras, the combination with a support,of an annular threaded member revolubly carried thereby includinginternal threads, an objective, an objective carrier comprising atubular extension slidably mounted in the threaded member and includingthreads adapted to mesh with the threads of the annular member, meansfor sliding the tubular extension until the threaded areas of thetubular extension and annular member lie adjacent, means for causing thethreaded areas to mesh rapidly through a turning movement of onethreaded area relative to the other, means carried by the support andtubular extension for preventing a turning movement of the tubularextension, a second means carried by the tubular extension and annularthreaded member for preventing the latter from turning until thethreaded areas are substantially in meshing position, said first namedmeans comprising a pin and a slotted guideway on the support and tubularextension for guiding the latter on the former.

10. In a focusing lens mount for cameras, the combination with asupport, of an annular threaded member revolubly carried therebyineluding internal threads, an objective, an objective carriercomprising a tubular extension slidably mounted in the threaded memberand including threads adapted to mesh with the threads of the annularmember, means for sliding the tubular extension until the threaded areasof the tubular extension and annular member lie adjacent, means forcausing the threaded areas to mesh rapidly through a turning movement ofone threaded area relative to the other, means carried by the supportand tubular extension for preventing a turning movement of the tubularextension, a second means carried by the tubular extension and annularthreaded member for preventing the latter froin turning until thethreaded areas are substantially in meshing position, said first namedmeans comprising a pin and a slotted guideway carried by the support andtubular extension for guiding the latter on the former, the slot in theannular threaded member releasing said web when said threaded areas arein a substantially meshing position.

11. A focusing lens mount for cameras comprising in combination, anobjective, a tubular extension carrying said objective, an annularthreaded ring rotatably mounted on the camera and supporting the tubularextension, said tubular extension including two portions, a smoothexterior surface on one portion and a threaded exterior on the otherportion adapted to mesh with the threaded ring, means for preventingrotation of the tubular extension relative to the camera, and a secondmeans for preventing rotation of the annular threaded ring only when thesmooth exterior surface portion of said annular member is in apredetermined position in which aaeaees the smooth exterior portioncontacts with the threads of the threaded ring, said second means beingreleasable by sliding said tubular extension until said threaded portionof the tubular extension is moved adjacent the threaded annular ring.

12. A focusing lens mount for cameras comprising in combination, anobjective, a tubular extension carrying said objective, an annularthreaded ring rotatably mounted on the camera and supporting the tubularextension, said tubular extension including two portions, a smoothexterior surface on one of said portions and a threaded exterior on theother of said portions adapted to mesh with the threaded ring, means forpreventing rotation of the tubular extension relative to the camera, anda second means for preventing rotation of the annular threaded ring onlywhen the smooth exterior surface portion of the annular member is incontact with the threads of the annular threaded ring, said second meanscomprising a web extending axially over a portion of the smooth exteriorsurface portion of the tubular extension, and a slotted guideway out inthe threads of the annular threaded member, the proportions of theweband guideway being such that said annular threaded ring may turn whenthe threaded portion of said tubular extension lies adjacent to thethreads of the annular threaded ring.

13. A focusing lens mount for cameras comprising in combination, anobjective, a tubular extension carrying said objective, an annularthreaded ring rotatably mounted on the camera and supporting the tubularextension, said tubular extension including two portions, a smoothexterior surface on one of said portions and a threaded exterior on theother of said portions adapted to mesh with the threaded ring, means forpreventing rotation of the tubular extension relative to the camera, anda second means for preventing rotation of the annular threaded ring onlywhen the smooth exterior surface portion of said annular member is incontact with the threads of the annular threaded ring, said second meanscomprising a web and slot connection between the annular threaded ringand the tubular extension, the web and slot being so positioned on thesmooth exterior surface of the tubular extension and on the annularthreaded ring that said parts may be disengaged when the threaded areaof the tubular extension lies adjacent the thread of the annularthreaded ring, whereby movement of said ring may, through engagement ofsaid threaded portion of the tubular extension, move the latter forfocusing the camera lens.

JOSEPH MIHALYI.

